In a bit of positive smoking-related news, the CDC has found that fewer nonsmokers are being exposed to cigarrette smoke. While in the past, as much as 84 percent of measured populations were found to have signs of nicotine in their system, more recent measures have found that percentage to be down by nearly half. Cotinine, a byproduct of nicotine, can remain in the blood for four to five days after exposure to the drug, and in this study only 46 percent of nonsmokers were found to have traces of it in blood tests.

The researchers behind this new work have speculated that smoking bans, which prevent lighting up in most public spaces, may have a great deal to do with the reduction in nicotine exposure among nonsmokers. They also point out that smoking prevalence is at an alltime low, with roughly one in five adults reporting continued smoking.

Dramatic reductions, however, were not seen in every sub-group in the study. Children aged 4 to 11 showed evidence of nicotine exposure at rates nearly 50 percent higher than the group average. Blacks also saw less of a decline than did whites or Mexican-American's in the study. Both of these specific groups, while different in their nicotine exposure underpinnings, illustrate areas in need of greater attention. 

Second-hand smoke contributes to a number of health issues, a fact that contributed heavily to the legislation that created many of the smoking bans. This research, drawn out of the National Health and Nutrition Examination Survey, should prove encouraging for those concerned about these policies' efficacy.